1. Field of the Invention
The present invention relates to a method for detecting the presence of microorganisms such as bacteria and the rate of proliferation of microorganisms with a piezoelectric vibrator, and to a microorganism detecting apparatus.
2. Description of the Related Art
Nowadays, consciousness regarding food safety has been growing, and early detection of putrefactive bacteria which deteriorates food, beverage, and the like is an important issue.
Conventionally, as means for determining whether or not putrefactive bacteria are contained in food, beverage, or the like, there have been used measurement methods such as immuno assay, enzyme-linked immuno sorbent assay (ELISA), gas chromatograph/mass spectrometry (GC/MS), liquid chromatograph/mass spectrometry (LC/MS), and the like. However, pre-treatment in these methods are complicated, and it is hard to say that accuracy of determination is sufficient. Accordingly, a method to take long time to incubate putrefactive bacteria is common.
This incubation method is to incubate putrefactive bacteria which have a possibility to exist in a sample solution for two to four days at incubation temperatures from 30° C. to 60° C. for example, and then perform visual examination of a colony. However, it is difficult to apply this method to a subject of examination which needs to be determined in a short period, such as food and beverages, and thus there is a problem that shipment after a short period from manufacturing is not possible.
Translated National Publication of Patent Application No. 2000-513436 (claims 1, 7, and 15) describes a method for identifying a biological sample, and describes that components which coupled to a sensor array are determined directly by measuring increase in mass on a surface thereof, that a method for detecting increase in mass on the surface is to use a crystal oscillator balance, and that the biological sample is fungi, viruses, or bacteria. However, the present invention is not described in this publication.